Low power and Lossy Networks (LLNs), e.g., sensor networks, have a myriad of applications, such as Smart Grid and Smart Cities. Various challenges are presented with LLNs, such as lossy links, low bandwidth, battery operation, low memory and/or processing capability, etc. One example routing solution to LLN challenges is a protocol called Routing Protocol for LLNs or “RPL,” which is a distance vector routing protocol that builds a Destination Oriented Directed Acyclic Graph (DODAG, or simply DAG) in addition to a set of features to bound the control traffic, support local (and slow) repair, etc. The RPL architecture provides a flexible method by which each node performs is DODAG discovery, construction, and maintenance.
Currently, mesh networks, such as LLNs, can take a long time to converge. In addition, existing systems allow parent selection changes (convergence) to take place anywhere within the DAG at each node's individual discretion. Due to these two factors, network oscillations may occur, as well as unnecessary changes during convergence (routing changes). For example, during the convergence period, child nodes may migrate to other parents and therefore change the conditions for their children which may necessitate additional changes in the network. In particular, when a node with a large number of children (and thus a large amount of traffic) changes a parent, many child nodes are affected, likely having a strong impact on path metrics (e.g., and latency), leading to further oscillation. Moreover, the new traffic that the aforementioned node directs via its new parent presents a heavy load to the new parent, and thus the new parent may also need to find an alternate parent as well, resulting in large scale network and traffic rerouting. To top it off, during this convergence process, messages which have been sent downward may traverse via a specific (pre-configured) route which may no longer be valid because the path between the sending node and a root of the DAG may have been reconfigured.